The American Petroleum Institute (API) is one of the largest regulating bodies when it comes to maintenance, repair and construction of above ground storage tanks. Typically, all storage tank owners and operators must have their tanks inspected by an API-certified inspector once every five years, or a quarter of the tank’s corrosion rate.

Whether you’re a first-time operator of these steel storage tanks or you’ve owned them for years, the API’s inspection processes can seem labyrinthine and daunting. In particular, the API 653 inspection standard, which covers the maintenance, inspection, alteration and repair of these steel field-erected tanks, tends to confuse many people.

Not sure what to expect from an API 653 tank inspection? To start preparing yourself — and your above ground storage tanks — for API-653 certified inspectors, read this beginner’s guide to what everyone should expect during these inspections:

General tank information and specifications

Before looking at your above ground storage tanks, API inspectors will first look at information about the tank’s construction, methods of release detection and spill control systems in place. Because all steel storage tanks must have a secondary containment area, it’s just as important to inspect spill control and containment as it is to inspect the tanks themselves.

Tank shell, bottom and roof inspections

During each API 653 inspection, the tank’s overall structure will be closely inspected. The inspector will look at the tank’s shell, bottom and roof using technologies like Ultrasound and radiography, which can help detect areas where corrosion is taking place.

Tank foundation and settlement pattern

The final step in the API 653 inspection involves the tank’s foundation and the manner in which it’s settling into the ground. The ideal tank foundation will settle uniformly, with no tilting or shifting out of plane. The inspector will also look for things like edge settlement and localized dispersions when examining the foundation.

Have any other questions or advice on the API 653 inspection for steel storage tank maintenance, inspection, alteration and repair? Get the conversation going by leaving a comment below.